How long has anyone's cat gone missing for?

i have a female, who went missing for two weeks and came back really changed. she was super friendly and had put on about 4lbs in weight. we vlikened her to amy winehouse going into rehab. my dad guessed she had probably been hanging out in the warehouse at the back of our place catching baby birds, judging by the ize of her,she hadnt gone hungry.the woods are probably providing her with enough mice etc to survive. i really hope you find her. dont give up hope yet xxx